Telephone switching system.



c. L. GOODIIUM.

TELEPHONE SWITCHING SYSTEM,

APPLICATION FILED SEPT. 7, 1915.

LQQ. Patented Nov. (S, EN?,

tra, sra'rns Arnulf y oniricaa4 f CHARLES L. GOQDRUM., or New roar.,V N. Y.,`Assie1\roa er nrSnAssmNMrNa-s r9 WESTERN ELECTRIC COMPANY, 'ING,B.1?OBATED,

.companion or new xonK;

TELEPHONE swrrcrrrive smurfen, 1

Patented NOV, 6, 1,91

Application led 'September 7, 1915. Sera1N.o.49,2,8f9.

To all whom it may'concem Be it known that I, CHARLES LANE Goon- RUM, a citizen of the United States, residing at New York, in thecounty of New York and State of New York, have inventedfcertain new and useful Improvements in Telephone Switching Systems, of" which the following is a full, clear, concise, and exact description. i

This invention relates to telephone switching systems, and more particularly lto improvements in order wire circuits as used in connection with the handling of trunk service between telephone exchanges, and has for its objects, first, to improve the telephonic transmissions, possibility of messages becoming confused, and third, to reduce the length of regular order-messages as transmitted by an A operator in requesting a trunk assignment from a B operator. V

In accordance with this'invention, an order wire circuit composed ofA individual line circuts from a pluralty of Iexchanges for service to a B position at another exchange, is provided with switching relays,

Vsignals individual to each exchange, 'anda tone signaling current supply. An .operatoris telephone circuit at the Bf position is normally disconnected from the order wire circuit and is not capable of being connected to more than one of the plurality .of entering order wire line circuits at the same time. The switching .operations are under the control of A operators at any ofthe distant exchanges, and take place automatically when an order wire key is depressed in the usual way. At the B position a signal lamp is lighted during the time the B operators telephone circuit is vconnected `to a distant exchange, thereby indicating from which exchange an order is `being received. In the drawing illustrating ,this invention there is shown at 1an A operators telephoneV circuit andy an order wire key 6 :assumed .to 'be located at an originating exchange, and similar equipment may be assumed to be present at `the points 2 and '3 which represent lother :originating Iexchanges.

Each of the order -wire `line circuits extending to exchanges 1, '2 and' are provided with similar individual equipment consisting of relays 10, 11 .and signal lamp 12 for @Xchange number .1a-relays 30,131 and second, to prevent the lamp .32 for exchange number 2; and relays 5.0, .51 and lamp A52 tor exchange 8. The master relay .35 being common to the .de vices associated with the `three line circuits, a condenser in .each side 4or ,the line circuits, indicated "as 17 and 18 in :the line to .ex-

change 1, areemployed -for the purpose of excluding battery current from thev B operators telephone Vcircuit and from the secondary w-inding44 of the transformer 43. .In .describing the .operation ,of this system` let vit be assumed that a subscriber, whose line .terminates in exchange A1, requests to be connected with a subscriber whose line terminates in ,the exchange at whichgthe B operators ,circuit 2,5 Yis located. An A yoperator at exchange 11depressesthe order wire key :6. The closure y of .contacts '7 and `8 of this key establishes a circuit from battery 40, through .the separate windingsof relay 10 and line conductors 4 and .5, .completing vcircuit through the cA-operators telephone set at ,exchange 1, thereby .eecting `the-operation .of the relay 10. Closureoi contacts 9 ,on reglay 10n0`W completes `a series circuit from battery 40 through switching relay -11 .and master relay 35 by way of conductor. 39,.,con'tacts :36 of relay 35 and conductors 19., 42 and VA2.3. Switching relay 11 now operates xsliglitl-yin advance of lmaster relay 35 ,as a result of the' closed copper ,secondary on the core ,of the master relay. This difference in time between the operation o thet-wo relays permits .the zcontacts 13 of the relay 11 to have established a shunt path aroiuid the. contacts 36 of relay '8.5 before the latter `contacts are opened. Therefore, after the relay :315

yhas operated, the path formed ,by contacts 13 .of relay 11 and conductor 20 are substituted for the 4irst path Vformed by contacts 36 of relay 35 and `conductor's427 19 and39. Signalilamp 12 connected-'inbridge i linecircuit, and contacts 14 and 15 .offthis relay close` a-,tal'king .circuit by means of conductors 21, '22, 4 `and 5 between'the "B Loperators ,telephone circuit 25 ,and the "A operators telephone'circuit .at exchange 1.

`lamp 12 remaining vliggghted, the 1 The signal A operator may omit the name of the originating exchange and only give the telephone numberof the subscribers line for which a trunk is desired. During the time this talking circuit is retained between exchange l and the B operators telephone circuit, the exchanges 2 and 3 are preventedv Vcircuit to exchange l. Although contacts 29 of relay 30 would now be closed, switching relay 31 would not operate on account of its circuit, by way of conductors 38 and 34, being open at the contacts 37 of master relay 35. The failure of relay 31 to operate permits the tone signaling current from transformer e3 to traverse contacts 28 of this relay and complete circuit over the line conductor 27, the operators telephone circuitatexchange 2, line conductor 26, one winding or relay 30, thence through the battery l0 to earth, thereby indicating to the seeking A operator that the B 0perator is busy. The same results would be present-with respect to the order wire circuit to exchange 3 in case an A operator at that point should seek connection with the B operator. Upon the order wire key 6 being released at exchange l, relays 10, l1 and35 are released and the signal lamp l2 is extinguished. The operations for either one of the exchanges 1, 2 and 3 are identical with respect to each other. VThere` fore, during the time either one of the exchanges may be connected to the B `0perators telephone circuit, the other two exchanges will be locked out and the busy test signaling current applied to the line circuits. rlhis system may be extended to cover any number' of originating exchanges by placing` additional contacts on the master relay 35 and equipping each additional order wire line circuit with a line relay, switching relay and signal lamp as described in connection with the circuits shown in the drawing. For the purpose of simplifying they circuit arrangement in the drawing, several battei-ies 40 and several transformer sets's are shown. It will be understood, however, that only one battery and one transformer set willbe'necessary in the operation of this system. What is claimed is: 1 i l 1. ln a telephone switching system, aplurality of ordering stations,an order receiving station, a line circuit extending from each of said ordering stations to said order receiving station, an operators .circuit at said order receiving station, a source of signaling current at said order receiving station normally connected tothe terminals of each Lof said lines, and switching means individual to and operated over each of said line circuits for associating said operators circuit therewith, and for disconnecting said source of signaling current therefrom.

2. ln a telephone switching system, a plurality of ordering stations, an order receiving station, a line circuit extending from each'of said ordering stations to said order receiving station, Van operators circuit at said Vorder receiving station, switching means individual to each of the said lines for associating said operators circuit therewith to the exclusion of the remaining ones of said line circuits, apsoui'ce of signaling current at the order receiving station normally coiinected with the terminals of each ofsaid line circuits through switching means individual thereto, and means controlled by any one of said switching means for rendering Said source of signaling current ineifective with yrespect to the liner circuit associated with the operated switching means but @Rec tive with respect to the remaining line circuits. i Y Y.

3. In a telephone switching system, a plurality of ordering stations, an order receiving station, a line circuit extending vfrom each of said ordering stations to said order receiving station, an operators circuit lat said order receiving station, switchingineans individual to and operated over each of said line circuits for associating said yoperators circuit therewith, a source of signaling current at the order receiving station normally connected with the terminals of each of said line circuits throughthe switching means individual thereto, and means controlled by the operation of an individual switching means for disconnecting said signaling cur- 'rent from the line associated therewith and for preventing the operation of the remaining ones of said switching means..

el. ln a telephone switching system, a plu-A rality of ordering stations, an order receiving station, a line circuit extending 'from each of said ordering stations to said order receiving station,an-,opei'ators circuit. at said order receiving station, a signal atsaid order receiving station'for each of said line circuits switching means individual to: and controlled* over each of said line circuitsfor connecting said operators circuit therewith, a source of signaling current at'said order receiving station normally connected to the terminals of leach of said line circuits through switching means individual thereto,

-means operated by any one of saidswitching meansfor operating the signal associatedtherewith and retaining said signal eifective during the period said operators circuit is held connected .with an associated line circuit, and means controlled by the operation of an individual switching means for disconnecting said signaling current from the line associated therewith Vand for preventing the operation of the remaining ones .of said switching means.

5. In a telephone exchange system, a plurality of ordering stations, an order receiving station, a line circuit extending from each of said ordering stations to said order receiving station, an operators circuit at said order receiving station, a signaling device at said order receiving station 'for each of said lines, switching means individual to and operated over each of said lines `for connecting the operatcrs circuit therewith and 'for operating the said signaling device associated therewith, a source of current at the order receiving station, switching means at the order receiving station and common to all of said line circuits for controlling the application of said source of current, and means under the conjoint control of the said common switching means and any one of the said individual switching means for excluding .the connection of the said opera; tors circuit with the remaining line circuits.

6. In a telephone exchange system, a plurality of ordering stations, an order receiving station, a line circuit extending from each of said ordering stations to said order receiving station7 a signaling device at said order receiving station individual to each of said lines, an operators circuit at said order receiving station, switching means individual to and controlled over each of said line circuits, means controlled by the operation of any one of said individual switching means for operating' said signaling device associated therewith and for connecting the operators circuit with the associated line, and means at said order Vreceiving station for disabling said signaling device associated with the remainder of said lines.

In witness whereof, I hereunto subscribe my namethis 2nd day of September A. D.,

CHARLES L. GOODRUM.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents,

Washington, D. C. 

